Determination of Organochlorine Pesticides and Polychlorinated Biphenyls in Soil and Sediment by Ion Trap Tandem Mass Spectrometry

KeyWord:OCPs  PCBs  GC-IT-MS/MS  soil  sediment

Abstract:

      A gas chromatography-ion trap tandem mass spectrometric£¨GC-IT-MS/MS£© method was established for the determination of 25 organochlorine pesticides£¨OCPs£© and polychlorinated biphenyls£¨PCBs£© in soil and sediment.The sample was extracted with hexane and acetone£¨1¡Ã1£¬by volume£© by accelerated solvent extraction£¨ASE£©£¬cleaned up by solid phase extraction£¨SPE£©.The MS/MS parameters were systematically investigated and optimized.Under the optimal conditions£¬the linear ranges of 17 OCPs ranged from 1.73 ¦Ìg/L to 220ª±8 ¦Ìg/L£¨except for endrin from 3.45 ¦Ìg/L to 441.6 ¦Ìg/L£©,with the method detection limits£¨MDLs£©of 0.049-0.274 ¦Ìg/kg,and the linear ranges of 8 PCBs ranged from 0.87 ¦Ìg/L to 110.4 ¦Ìg/L,with the MDLs of 0.028-0.049 ¦Ìg/kg.The average recoveries of 25 OCPs and PCBs at two spiked concentration levels of 0.345 ¦Ìg/kg and 3.45 ¦Ìg/kg were in the range of 70%-108% with relative standard deviations£¨RSDs£© of 5.0%-14.0%.The method was applied in the determination of 25 OCPs and PCBs in complex soil and sediment samples. The results showed that£¬compared with the GC-MS method£¬the IT-MS/MS method could effectively eliminate a large number of interference factor£¬reduce the possibility of false positive and false negative results£¬and improve the accuracy of quantitative results.